Which is easier for you to find: a UL BPer to backpack with or a woman to spend your life with?
I and a dozen other whackos went on Eugene's crazy rim-to-rim-to-rim trip last year and many are going on Mike's Zion trip in April. So it seems to me that UL BPer types are easy to hook up with (at least if you stay in your own quilt). Whereas, many of us looked for years for the right person to settle down with (although my wife did more extreme BPing, climbing, travel and expeditions than I had before we hooked up).
There is always a "price of admission" to be in relationship since no two people are ever perfectly compatible, interested in exactly the same things, have the same sexual tastes, or like exactly the same diet. Is her carrying lots of weight while backpacking a price you're willing to pay to in a BF-GF relationship with her? Turning it around, is being in a harmonious relationship worth enough to you to be patient with her as she adjusts to a BPing mindset?
I'm pretty UL now. I wasn't during the first years I camped and backpacked. You seem to be insisting on a very steep learning curve by the GF. If she was after you to change your bad habits (house keeping, dress, table manners, whatever) so quickly, would she be as much fun to hang out with?
If the water thing really is a paranoia (an irrational fear) AND she wants to rein it in, she could slowly, slowly, desensitize herself with calm exposures to ever so slightly less controlled settings. Trying to convince someone to not have a paranoia doesn't work.